Projection arc-controlling system



Aug. '17 1926. 1,596,254

A. D. STANDEFORD PROJECTION ARC CONTROLLING SYSTEM Filed May '7, 1917 3 Sheets-Sheet 1 I an A TTORNEY.

WITNESS:

Aug. 17 1926. 1,596,254

I A. D. STANDEFORD I PROJECTION ARC CONTROLLING SYSTEM Filed Mm! 1917 V 3 Sheetfis-Shent 2 [I I 11/ alllllll 1 11/ 111 III] III I I 1 1 [Ill/II l1 Afiwm INVENTOR.

ATTORNEY.

WI TNIiSS:

Aug. 17 1926. r 1,596,254

A'. D. STANDEFORD PROJECTION ARC CONTROLLING SYSTEM Filed May '2, 1917 3 Sheets-Sheet 5 16'! 70 I67 3 Z66 I I 14L INVENTOR." U .9 flmizzflfiaizda ard,

A TTORNE Y.

WITNESS.-

Patented Aug. 17, 1926.

UNITED STATES PATENT OFFICE- PROJECTION ARC-CONTROLLING SYSTEM.

Application filed May 7, 1917. Serial No. 167,149. I

This invention relates to a new and useful system embracing means for regulating the voltage and amperage of electric circuits, and while applicable to various kinds of circuits it is particularly advantageous when employed in connection With the arc lamp circuit of motion picture and other projection machines where constant predetermined light values are desired. I

The invention further embraces automatic means whereby the circuit including the motor which drives the carbon feeding mechanism, is automatically opened should the arc become extinguished from any cause, and is retained in open condition until the arc is again established; thus obviating danger of fire by having the arc ignite in the absence of the operator.

In order that the invention may be fully understood, reference will now be made to the accompanying drawings, in which:-

Fig. 1 is a side elevation, partly in section. of apparatus employed in carrying out the invention.

Fig. 2 is a broken vertical section on line IIII of Fi 4 of a manually adjustable resistance em odied in the motor circuit.

Fig. 3 is a brokenvertical section, enlarged, on line III'III of Fig. 1, of a portion of the carbon feeding mechanism. I

Fig. 4 is an enlar ed, horizontal section on line IVIV of-Fig. 1, of a box containing the motor and associated parts.

' Fig. 5 is a vertical sect-'on on line V of Fig. 4, of a portion of the carbon feeding mechanism.

Fig. 6 is a vertical cross section on line VI of Fig. 4, showing a part of the carbon feeding mechanism. 4

Fig. 7 is a vertical cross section on line VII of Fig. 4, with some of the parts re moved.

Fig 8 is a side elevation of manually controlled means embodied in the carbon feeding mechanism.

Fig. 9 isan enlarged longitudinal section on line IXIX of Fig. 8. 1

Fig. 10 is an irregular vertical'section of a solenoid and associated parts embodied in the motor -circuit, taken on line X of Fig. 4

v Fig. 12 is a diagram of the different cir- Fig. 11 is a cross section on line XI of cuits and the manually controlled and automatically controlled means employed in carrying out the invention.

Fig. 13 is a fragmentary elevation of two racks and a pinion for moving the arc carbons toward or away from each other.

Referring first to the diagram Fig. 12, 1 designates the main line circuit which connects with the arc circuit 2 through a manually-controlled switch 3.

4 designates a manually controlled variable resistance embodied in the arc circuit 2, to initially regulate the amperage and the voltage of said are circuit.

'8 designates the motor for driving the carbon feeding mechanism. Said motor is in a circuit parallel to the arc circuit 2 and having its poles 9 and 10 connected to opposite sides of said arc circuit.

Said motor circuit embodies a wire. conductor 13 leading from the pole 9, a circuit closer 14 connected to said conductor 13, a wire conductor 15 leading from said circuit closer 14 to the motor 8, a wire conductor 16 leading from the motor 8, a man ually adjustable resistance coil l'Z, a wire conductor 18 connected to said resistance coil 17, a snap switch 20 connected to said conductor 18, and a wire conductor 21 leading from the snap switch to the pole 10. The circuit c1oser14 embodies a gravity armature 26 connected to one end of t e conductor 13, and a fixed contact point 27 connected to one end of conductor 15. An electromagnet 25 in series with the arc circuit 2, is provided for holding the circuit breaker 14 in closed position.

The resistance coil 17 has adjustable contact points 30 and 31, spaced apart and arranged to be shifted simultaneously, as will hereinafter ap ear. The contact oint 30 is connected to the conductor 16 an the contact point 31 is connected to a wire conductor 35 leading to acircuit breaker 36, which connects with the conductor 16 through a wire conductor--37.

The circuitbreaker 36 consists of a fixed the conductor 35. A solenoid 45 having a core 46, is, provided for forcing the contact 41 into engagement with the point 39.

i The solenoid 45 has a plurality of coils of different lengths connected at one end to a wire conductor 47, and having their opposite ends leading to respective contact points 48, arranged to be engaged in pairs by a bridge 50 on a pivoted member 51 connected to a manually adjustable contact point 53, engaging a resistance coil 54 connected at one end to a conductor 55. As disclosed by the diagram the coil of the circuit breaker 36 is in shunt with the coil of the circuit closer 14.

In practice, the switch 3 is first closed to establish connections between the main line circuit 1 and the arc circuit 2, and the manual resistance 4 is adjusted to admit the desired amperage to the are 57. The are circuit 2 remains open until the arc is manually struck. The electromagnet 25 then becomes energized and automatically closes the motor circuit, the sna switch 20 having been previously close by the operator. After the lamp-carbons A have been manually separated to meet normal working conditions "they are fed toward each other as they are consumed, by the motor 8 and its intervening gearing.

The speed of the motor is then manually regulated as follows: The contact point 36 is adjusted to throw in suflicient resistance to reduce the motor speed slightly below normal and thus slightly increases the arc gap above normal. Adjustment of said contact 30 adjusts the contact 31 relative to the open end of the coil 17, to cut out sufiicient resistance to allow the motor speed to slightly increase and thus reduce the gap between the carbons slightly below'normal. The contacts 50 and 53 are then adjusted to permit the solenoid 45 to operate efficiently through a widerange 0f amperage. When an arc of normal length is obtained the contacts 39 and 41 are manually adjusted toward the solenoid core 46 until the latter forces the contact 41 into engagement with the point 39, thus closing the circuit breaker 36. When this occurs the motor circuit current, which heretofore passed through the resistance coil 17 from the point 30 to the conductor 18, is shunted around that portion of the coil between its open end and the point 31 through the conductor 37, the cireuitbreaker 36 and the conductor 35. By thus shunting the motor circuit curreht around a portion of the resistance coil 17, the motor 8 is speeded up and reduces the length of the arc gap.

The are is then automatically controlled as follows: Should the voltage in the main circuit increase above normal and tend to reduce the arc gap below normal, the energy of the solenoid 45 is proportionally increased, resulting in its core 46 being drawn away from the contact 41, which then instantly moves out of engagement with the point 39 and cuts out the circuit through the conductor 37, thecircuit breaker 36 and the conductor 35. All of the motor circuit current then passes through that portion of the resistance coil 17 between the point 30 and the conductor 18. This added resistance reduces the speed of the motor until the length of the arc becomes normal. Should the length of the arc increase above normal from any cause, the additional resistancedue to the lengthening of said are proportionally deenergizes the solenoid 45, leaving its core 46 free to move outwardly and force the contact 41 against the point 39. This cuts out the resistance between the points 30 and 31 and permits the motor to speed up until the arc is again normal.

Should the arc circuit become interrupted the motor circuit is instantly interrupted by the automatic opeinng of the circuit closer 14, and the motor 8 remains at rest until the arc circuit is reestablished.

From the foregoing description it is apparent that the length of the arc is automatically maintained through the intermediacy of the circuit breaker 36 and associated parts, after the manual adjustments above-described have been made. Efliciency of said circuit breaker. 36 is attained by relieving it of all work other than closing the contacts 41 and 39, hence it instantly responds to any fluctuations in the arc circuit and quickly changesthe resistance in the motor circuit, which results in adjusting the length of the arc to maintain relatively constant amperage at said are.

The efiicient results above described are" also partly due to spacing the contact points 30 and 31 such distance apart as to render any change in the arc length so gradual as to obviate undue disturbance to the are crater. Hence a relatively fixed and undisturbed illumination is maintained on the screen when the system is employed in the projection of pictures.

Referring now to the mechanical construction of various parts it will be found that Fig. 4, discloses the contact oints 30 and 31, pivotally-mounted upon-t e cylindrical terminal of a lever 60 and yieldingly-held in contact upon the exposed-portion of the resistance coil 17 by springs 61 and 62, respectively. Lever 60 is secured at one end upon a vertical shaft 63, journaled at its lower end in a bearing 64 and provided at its upper end with a rectangular socket 65, to receive the corresponding terminal of a short shaft 67 provided at its upper end with an indicator 68, whereby it may be rotated to adjust the contact points 30 and 31 back and forth upon the coil 17. All of the aforementionedpartsare located in a box 69, excepting the pointer 68 which extends over the top of said box and is adapted to coact with a graduated segment (not shown), so that the position of the contact points 30 and 31 with relation to the coil 17, can be readily ascertained by the operator. The socket connection between the shafts 63 and 67 permit the to of the box 69 to be removed without distur ing the lever 60 and the contact points 30 and 31. A coil sprin 76 (Fig. 2) interposed between the top of t 'e bearing 64 and the lever 60, creates sufficient friction to hold said lever at any point of its adjustment until manually moved.

The solenoid 45 .of the circuit breaker 36 is mounted upon a bracket 80, secured to a block of insulation 79, fixed upon the upper surface of the bottom of the box 69. The

hollow core 46 of said solenoid has a member 81 adapted to be adjusted toward or away from the contact 41, which together with the contact 39, is carried u on a rack 83 adapted to be adjusted vertica y by a pinion 84, to bring the contact 41 into the desired relation with said ad'ustable member 81. The pinion 84 is fixe upon a shaft 85 provided with a knurled wheel 87, whereby it may be rotated. The rack 83 extends through a pair of ides 88, fixed to the metallic casmg of t e solenoid 45, which also has bear-. in s 89 in which the shaft 85 is journaled.

he gearing between the motor 8 and the racks 90, whereby the carbons A are fed,"

comprises a shaft fixed to the motor shaft 1 96 by a set screw 97, a worm 98 slidable upon the reduced end of the shaft 95 but.

driven thereby through the intermediacy of a pin 99, a worm wheel 100 driven by the worm 98 and fixed upon one end of a shaft 105, a worm 106 fixed upon the opposite end of the shaft 105, a worm wheel 107 driven by said worm 106 and fixed upon one end of a shaft 108, a bevel gear wheel 109 fixed upon the opposite end of the shaft 108, a-bevel wheel 110 driven by said bevel gear 109 and fixed upon a shaft 111 journaled in a yoke 112, a bevel gear wheel 115 fixed upon a shaft 111, a bevel gear wheel 116 driven by the bevel gear 115 and fixed upon the lower end of a shaft 117 journaled in a yoke 118, a hollow rectangular shaft 120 fixed -to said shaft 117 and telescoping over the lower-end of a corresponding shaft 122,'fitting at its upper end into a hollow rectangular shaft 123 telescoping over the,

corresponding end of a shaft 124, journaled in a yoke 125 and provided with a bevel gear 126, a bevel gear 127, fixed upon a transverse shaft 129 carried by a yoke 139 and provided with a fixed bevel gear 135, which drives a bevel gear 136 fixed upon a shaft 138 journaled in a bearing 128 and provided with av worm 140, which drives a worm wheel 141 fixed u on a tubular shaft 160, adjustably mounte upon a feed rod 145 and'provided at one end with aknob 146. Said rod 145 has a universal connection 147 with a short shaft 148, carrying a pinion 150 whereby the lamp racks 90 are adjusted in opposite directions to increase or diminish the gap between the carbons A.

The I knob 146 provides manual means whereby the arc may be quickly struck without actuating the entire train of gearing above-described. This is accomplished by means for throwing the worm 140 down out of mesh with the Worm wheel 141 (see arrow Fig. 8) so that the same may rotate freely with the knob 146. As disclosed more clearly by Figs. 8 and 9, the worm wheel 141 is fixed upon the tubular shaft by a set screw 161. Said tubular shaft 160 has a slidable sleeve 163 provided at one end with a knob 164, and at its opposite end with a loose collar 165, connected y a pin -166 to a bell-crank 167, fulcrumed at 168 and hearing at its free end upon. a slidable pin 170, carrying the bearing 128. By drawing the knob I 164 backwardly against the knob 146, the bell-crank 167 is actuated to move the pin 170 longitudinally and throw the worm 140 out of mesh with the worm wheel 141, so that the same can turn freely and allow quick adjustment of the carbons 90 as above-stated. When the knob 164 is released, the worm 140 is automatically thrown into enga ement with the worm wheel 141 through t e intermediacy of a coil sprin 180, interposed between a collar 181, fixe to the pin 170, and one of the guides 182 in which the pin is slidably mounted.

The guides 182 are carried by a bracket 10. 185 mounted upon the tubular shaft 160.

The bracket 185 is prevented from rocking on the pin 170 and thus throwing the worm wheel 141 out of proper relation with the worm 140, by means of said in 170 and 1 a finger.187 projecting from the racket 185 through the forked end of an arm 188on the bearing 128.

That portion of the train of gearing from worm'98 to the worm 107, is arran ed within 11. a small reservoir 200 placed within the box 69. Said reservoir 200 is filled with lubri-' so that as the same rotates the oil will be carried to the carious portions of the gearing 11k within the reservoir and reduce friction to a minimum. The oil is prevented from assing out of the reservoir throu h the arge opening 201, through which t e shaft 95 projects, by a. collar 2.02 integral with said 18 shaft. 1 s v By slidably mounting the worm 98 upon the reduced end of the shaft 95, the motor shaft96 is relievedof all longitudinal movement from end thrust incident to driving the 1 train of gearing above-described, as said worm 98 is free to move longitudinally to a limited deg ee when yielding to the resistance due to driving the worm 100. Longitudinal movement of the worm 98 is "limited by a fiber stop 205, secured in one side ofithe reservoir by a set screw 206.

Having thus described my invention, what I claim and desire to secure by Letters Patent, is:- v

1. In a system of the character described an arc circuit, a motor arranged to travel in one direction and connected in parallel with said are circuit to feed the arc electrodes towards each other only, a resistance in series with the motor circuit, and means responsive to conditions in the are circuit for short circuiting a portion of said resistance.

' 2. In a system of the character described, an arc circuit, a motor connected in parallel with said are circuit to feed the arc electrodes towards each other, a manually adjustable resistance in series with said motor, a coil connected with and responsive to conditions in said are circuit, a resistance connected to the arc circuit and in series with said coil, and a circuit breaker actuated by said coil and arranged to short circuit a portion of the first-mentioned resistance to speed up the motor.

3. In asystem of the character described, an arc circuit, a motor connected in parallel with said are circuit to feed'the arc eleci 4. In a system of the character described,

an arc circuit, a motor connected in parallel with said are circuit to feed the arc electrodes towards each other, a circuit closer for closing the motor circuit and having one contact connected to the arc circuit and the other to said motor circuit, magnetic means in series with the arc circuit for holding the circuit closer in active position, a resistance in series with said motor, a coil connected with and responsive to conditions in said are circuit, a resistance connected to the arc circuit and in series with said coil, and a circuit breaker actuated by said coil and arranged to short circuit a portion of the first-mentioned resistance to speed up the motor.

In testimony whereof I afiix my si nature.

ARCHIE D. STANDEF RD. 

